A. Field of the Invention
The present invention relates generally to marketing data collection systems, and more particularly to a method and apparatus for identifying individual members in a plurality of monitored areas for use with television audience measurement and marketing data collection systems.
B. Description of the Prior Art
Various program identification and television audience measurement and marketing research systems are known. Such systems fall into various categories. One category includes manual systems where the viewer keeps a diary indicating, such as programs viewed and products purchased. Such manual systems are prone to inaccuracies resulting from the entry of erroneous data that may be intentionally or unintentionally entered and are slow in acquiring data.
Another category includes partly automated systems that require active participation by the viewer or marketing member. U.S. Pat. No. 4,546,382 to McKenna et al. describes a television and market research data collection system wherein the panelist uses an optical scanning device for scanning bar codes of purchased products and a channel selector to enter channel numbers to answer questionnaire questions. U.S. Pat. No. 4,331,973 to Eskin et al. describes a system wherein the panelist presents a panelist identification card to cooperating retail stores where the panelist identification card is scanned by a universal product coding (UPC) scanner along with purchsed products. Such requirements for active participation by the individual audience or marketing members advantageously is minimized or avoided.
Another category includes systems generally limited to televison audience measurement applications. For example, U.S. Pat. No. 4,652,915 to Heller, III describes a system for identifying the presence of TV viewers where the viewer wears a headphone which remains activated to receive audio by transmitting an acknowledgement signal in response to periodic polls.
U.S. Pat. No. 3,056,135 to Currey et al. issued Sept. 25, 1962 and assigned to the same assignee as the present aapplication describes a method and apparatus for automatically determining the listening habits of wave signal receiver users. The method disclosed in Currey et al. provides a record of the number and types of persons using a wave singal receiver by monitoring the operational conditions of the receiver and utilizing both strategically placed switches for counting the number of persons entering, leaving and within a particular area and a photographic recorder for periodically recording the composition of the audience. A mailable magazine provides a record of both the audience composition and the reciver operation information for manual processing by a survey organization. Thus a disadvantage is that acquiring data is slow and further many viewing audience members object to being identified from the photographic record.
U.S. Pat. No. 4,644,509 to Kiewit et al. issued Feb. 17, 1987 and assigned to the same assignee as the present application discloses an ultrasonic, pulse-echo method and apparatus for determining the number of persons in the audience and the composition of the audience of a radio receiver and/or a television receiver. First and second reflected ultrasonic wave maps of the monitored area are collected, first without people and second with people who may be present in the monitored area. The first collected background defining map is subtracted from the second collected map to obtain a resulting map. The resulting map is processed to identify clusters having a minimum intensity. A cluster size of the thus identified clusters is utilized to identify clusters corresponding to people in an audience. While this arrangement is effective for counting viewing audience members, individual audience members can not be identified.